Countdown to DOOMSDAY! is a top-down 2D stealth action game with an emphasis on secrets, puzzle-solving and time management.

The player controls Captain Crumpitt, an anxious military officer that has to navigate through the Burpenson Air Force Base to solve puzzles in dedicated rooms in order to uncover  individual letters which composes a secret code, each of them encoded for printing into fax machines scattered all across, that they must input in the terminal found in the office of his “knocked out” superior, General Griffin, in which the player started, before the time limit of 30 minutes lapses.

While exploring the base, the player will occasionally have to deal with enemy soldiers that invaded the base with the order to arrest your unruly superior. They will have the choice to sneak through them undetected or shoot them down with the two weapons they can obtain.